Fire extinguishing apparatus



May 28, 1940. E. GEERTZ FIRE EXTINGUISHING APPARATUS Original Filed May 20, 1938 manica May 2s, 1940 "UNITED STATES FIRE EXTINGUISHING APPARATUS Eric Geerts, Aurora, Ill., assignor to Cardox Corporation, Chicago, lll., a corporation of Illinois original application May 2o, 193s, serial No.

209,151. Divided and this application November 1'1, 193s, serial No. 241,035

13 Claims.

This invention relates to new and useful improvements in apparatus for employing and making available for use liquid carbon dioxide as a re extinguishing medium, and is a division of my application Serial No. 209,151, illed May v20, 1938. Y o

Carbon dioxide is commonly used at the pres-l ent time as a fire extinguishing medium. When it is essential to have available for use large quantities of carbon dioxide, the prevailing practice is to store the liquid carbon dioxide in comparatively small cylinders or drums which are arranged and interconnected to form a bank or battery. The carbon dioxide is discharged from the top of the several cylinders in the form of gas. The temperature of the carbon dioxide is permitted to vary in accordance with variations in the temperature of the surrounding atmosphere and, for that reason, the cylinders must be constructed to withstand high working pressures. Due to this lack of control of the temperature and pressure of the stored carbon dioxide, it has not been allowable to illl 'the internal'volume of the cylinders with more-than 68% of liquid. The container weight and`cost per pound of capacity, therefore, is very high.

The effectiveness of carbon dioxide as a fire extinguishing medium. of course. depends on its ability to smother the flre by excluding oxygen. Carbon dioxide gas, although heavier than air, is seriously affected by the currents of heated air which rise from theiire and for that reason, the hotter the re, the 'less eiective or efcient carbon dioxide gas is as an extinguishingpmedium. The discharge of carbon dioxide gas from the battery of cylinders will bring about evaporation of additional liquid in the cylinders. This vaporization of liquid carbon dioxide in the cylinders will result in refrigerat'ing the remaining liquid. If the discharge of gas continues for a suilicient length of time, the temperature of the remaining carbon dioxide liquid will be lowered to 70 F., the temperature at which the liquid carbon dioxide will solidify, and further discharge of the extinguishing medium will cease.

This solidication of the remaining liquid carbon dioxide will occur asa result of continuous or substantially continuous discharge of approximately three quarters of the original quantity of liquid. l

Therefore, in addition to being unable to fill the entire internal volume of the cylinders with liquid carbon dioxide, approximately one-quarterV of the liquid which is stored in the cylinders is not available for use if the fire being extinguished is of acharacter to require discharge of more than three-quarters of the original quantity.

The primary object of this invention is to provide apparatus for making carbon dioxide avail- -able for use as a fire extinguishing medium without encountering the defects and disadvantages inherent in present day methods.

A further important object of the invention is to provide apparatus for employing and makm ing available for use at a low storage cost, large quantities of liquid carbon dioxide at controlled constant subatmospheric temperatures and corresponding lowV vapor pressures.

A still further object of the invention is to provide apparatus for employing liquid carbon' dioxide as a. fire extinguishingmedium in which the liquid is conditioned so as to produce a much higher percentage of yield of snow when discharged to the atmosphere than is possible with methods and apparatus now in common use.

Another object of the invention is to provide apparatus for employing carbon dioxide as a lre extinguishing medium wherein a larger quantity by weight of carbon dioxide per unit of container volume and weight is provided than has been possible heretofore.

Still another object of the invention is to provide a nre extinguishing-medium which is especially effective in combating gasoline, oil, Wood, electrical and coal mine fires; which is especially effective in preventing the occurrence of re-flash in any type of re, and which will enable re fighters tomore closely approach extremely hot lires. y

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawing forming a part of this specication and in which like numerals are employed to designate like parts throughout the same, y y

'I'he figure diagrammatically illustrates the fire extinguishing apparatus embodying this invention and its method of use to extinguish different types or kinds of hostile fires.

, In the drawing, wherein for the purpose of illustration are shown the preferred embodiments of this invention, the reference character 5 designates a building which is intended to be representative of alltypes and styles of building in which fire hazards may exist; for example, private residences, apartment houses, office buildings, garages, service and repair shops,

manufacturing plants, etc. Within this building |A 5, there is illustrated a room or confined space 8 which the owner or occupant desires to protect from a hostile fire by means of a sprinkling system I, with its discharge nozzles I. or by means of an ambulant discharge which may take the form of a flexible hose 8 with a suitable discharge nozzle III. Within the building 5, there also is illustrated an object II which may take the form of any stationary or substantially stationary piece of equipment or apparatus which can be protected by a non-ambulant discharge device I2 which may assume any desired and eillcient form fox` accomplishing. the intended results.

Exteriorly of the building l, there is illustrated a storage pile I8 which may be formed of any combustible material, such as coal, wood, grain, or the like. This storage pile I3 may be protected from fire hazards by means of a non-ambulant system of discharge nozzles I4 associated with a supply line I5 or by means of an ambulant discharge device which may take the form of the long perforated pipe I8 which is connected to a flexible supply conduit II.

While the objects designated by the reference characters 5, 6, II and I3 are representative of all diil'erent types of objects or things which should be protected from fire hazards, it is to be understood that the use of this fire extinguishing system and method is not in any way to be limited to the protection of objects and things of the character which has been illustrated, but is applicable to all objects and things which require lire protection. It is to be understood. also, that this system and method is not to be limited to the particular forms of discharge devices which have been diagrammatically illustrated.

Properly located with respect to the various sources of hostile lires is a heavily insulated container I8 of large capacity. 'I his container unit may consist of one tank or a series of tanks enclosed in a single heat insulating shell. The container unit I8 preferably should have a capacity of several hundred pounds of liquid carbon dioxide, and may contain several tons of the liquid, depending upon the character of the hazard to be protected. Of course, where the system is employed to protect large apartment houses, ofilce buildings, or a factory, it may be necessary to provide two or more of the container units I8. It is to be considered that such an expansion of the illustrated system falls within the scope of the invention. 'I'his container unit I8 should be designed to withstand a working pressure of approximately 500 pounds per square inch, or, more specifically, the vapor pressure at 32 F., which is 505 pounds per square inch absolute. Of course, container units capable of withstanding a higher working pressure may be employed, but as the ability to withstand greater internal pressures is not essential or desirable, the use of container units adapted to withstand working pressures appreciably in excess of 500 pounds per square inch will materially add to the initial cost of the installation and will thereby eliminate from or deprive the system of one of its most valuable features.

. Properly communicating with the lower portion of the container unit I8 is a pipe line I8 which extends to a readily accessible location and is provided at its extremity with a coupling 20 by means of which a transportable container, such as a railway tank car or road tank vehicle, may be connected to the said unit. .The railway tank car or road vehicle is intended to transport from a suitable source of supply to the location of the coupling 20, liquid carbon dioxide maintained at a desired subatmospheric temperature, not to exceed 32 F.. at the corresponding vapor pressure. This low. temperature liquid carbon dioxide is charged by any suitable method or means into the storage container unit I8. By transporting the liquid carbon dioxide at this low temperature and vapor pressure, a great reduction in the weight of the transport container per ton of capacity may be provided, with the result that handling costs are considerably lower than can be obtained when the carbon dioxide is transported at the uctuating temperatures and corresponding vapor pressures which would result ifv the temperature of the liquid carbon dioxide being transported were permitted to vary with the temperature variations of the surrounding atmosphere.

One of the features of this invention is to maintain the liquid carbon dioxide stored in the con tainer unit I8 at a subatmqspheric temperature which will not exceed 32 F., and preferably to maintain the stored liquid at the temperature at which it is charged into the unit I8. In view of this fact, it is possible to substantially iill the internal volume of the unit I8 with liquid carbon dioxide notwithstanding the low working pressure of the unit. 'I'his makes possible the storage of amuch larger quantity by weight of carbon dioxide per unit of container volume than would be possible if the carbon dioxide were stored at atmospheric temperature. It also makes possible a much lower cost per unit of storage capacity.

Associated with the container unit I8 are two different means for maintaining the liquid carbon dioxide at its charging temperature. One of these means consists of a standard commercial refrigerating plant 2| which has its evaporator,

coil 22 arranged within a dome 23 which is in open communication with the top of the container unit I8. As it is impossible to insulate the container unit against the penetration of any` heat whatsoever, the heat which does penetrate will cause some of the liquid carbon dioxide to evaporate. 'I'he gas which forms as a result of this vaporization will rise from the liquid bath and will contact the-coil 22. This contacting of the gas with the surface of the coil will cause the gas to condense and the condensation will be returned by gravity to the liquid bath. It has been determined that a coil of much less surface area can be employed with this arrangement than would be possible if-the coil 22 were located beneath the surface of the liquid bath. By such refrigeration storage of any quantity of carbon dioxide may be had over indefinite periods with no gas loss whatsoever.

The second means for maintaining the liquid carbon dioxide at the sub-atmospheric temperature at which it is charged in the container unit I8 consists of the pop-oil' or relief valve 24. This valve 24 may be of any desired and well known construction and is intended to be set or adjusted to open at the predetermined vapor pres- 'through the insulation of approximately 1,200.

bleeding of gas to the atmosphere will be accom-y panied by vaporization of a like amountk of the remaining liquid carbon dioxide. This vaporization is accompanied by or results from absorption of heat from the remaining liquid Kand brings about refrigeration of this liquid. This refrigeration of the liquid lowers its temperature and the corresponding vapor pressure until the pressure drops below the operating pressure of the valve 24.-

It will be appreciated, therefore, that at the expense of the loss of a comparatively small fraction of the stored liquid, the remaining liquid may be maintained at the desired storage temperature. This loss of carbon dioxide is not excessive and can be readily calculated since lit would be theratio of the heat loss in B. t. u. per hour to the latent heat of carbon dioxide at the stored temperature. For example, at 0 F., the latent heat is 120 B. t. u. per pound. A typical storage unit of approximately eight tons liquid carbon dioxide capacity has a rate of heat penetration B. t. u. per hour. Thus, the gas loss involved in maintaining the lowvpressure in the container unit would be a ratio of 1,200z120, or approximately ten pounds per hour. Theloss in this typical case amountsto approximately 11/2% in each twenty-four hours. 'I'his loss is less than the sublimation loss usually encountered in storing and handling solid carbon dioxide in the i form of dry ice".

It will be appreciatedthat the refrigerating unit 2| and its cooling coil-22 may be employed in combination with the pop-off or relief valve 24 to provide several dierent modes of operation.

For example, it is very desirable to employ a pop-olf valve 24 as a safety device which will function in the event of failure of the refrigerating apparatus. It will be appreciated, of course, that the refrigerating` apparatus will be provided with any conventional form of temperature or pressure control which will cause the refrigerating apparatus to operate periodically only when it is necessary to extract heat from the carbon dioxide stored in the unit i8. Thisautomatic control, not shown, for the refrigerating unit can be set to maintain the carbon dioxide at a desired subatmospheric temperature. The relief valve 24, operating `in combination with the refrigerating apparatus, can be set to open at a pressure in excess of the pressure at which the refrigerating apparatus will start to operate. Therefore; in the event of failure of the refrigerating apparatus, the valve 24 will operate to effect cooling'of the carbon dioxide as a result of bleeding of gas to the atmosphere.

Of course, other methods of employing a relief valve in combination `with a'refrigerating unit may be used. For example, thecooling coil 22 may be connected in a refrigerating system which is employed for other purposes in connection with the building in which it is housed. This refrigerating systemL may be operated with minicurrents rising from the ilre.

low temperature carbon dioxide for the purpose of maintaining the container unit il properly filled withthe iire extinguishing medium.

Suitable manually controlledvalves 24 are located at strategic points in the main supply or pipe lines 2l while a conventional expansion valve 25' is employed in the lines 21 of the. refrigerating apparatus. .By means vof valves 2l, selective delivery of the refrigerating medium to the various pipes of discharge devices maybe provided as desired.

It has been determined by extensive experimental work that liquid carbon dioxide discharged at a' temperature which does not exceed 32` F.,

is `a much more emcient and effective fire extinguishing medium than carbondioxide gas released at atmospheric temperature. For example,

a much higher percentage of yield of snow is.

lthe liquid carbon dioxide is discharged, the greater the percentage of yield of snow. This increased yield of snow provides a heavier blanket'for smothering the fire by excluding oxygen from the same, and is not displaced by the, natural air This great yield of snow provides the discharge medium with 1 greater mass-which permits the medium to be by the tire, are very effective in' preventing ref iash. The increased cooling eifect the larger yield of snow has upon the material being consumed by the ilre, vpermits iire ilghters to more closely approach the location of the re. The density of carbon dioxide stored at low temperatures as compared to its density when released to the atmosphere gives a much greater increase in volume thanis provided when the carbon dioxide is stored at atmospheric temperature. The density of liquid carbon dioxide at 0 F. is 64 pounds per cubic-foot, and when expanded in the atmosphere, its density is 0.12 pound per cubic foot. Carbon dioxide stored at this low temperature, therefore, increases in volume 540 times. The expansion of carbon dioxide stored at 70 F. is only'about one-half as greatas the expansion which occurs when the carbon dioxide is stored at 0 F.

It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same,A and that various changes in the shape, size,` and arrangement of parts may be resorted to without departing from the spirito! the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

l. A nre extinguishing system comprising an insulated storage `container having a working pressure substantially below the vapor pressure of carbon dioxide .at atmospheric temperature and adapted to be illled substantially to its volulmetric capacity with liquid carbon dioxide lat' a subatmospheric temperature, the corresponding vapor pressure of which will not exceed the working pressure of the container, means for eifectlng refrigeration of the carbon dioxide while maintaining all of the same stored in said container by condensing vapors in the vapor space of said container at a rate which vwill prevent a rise in vapor pressure above the working pressure of the container, and means for conducting the liquid carbon dioxide at approximately its stored subatmospheric temperature to a point oi' use.

2. A iire extinguishing system comprising an insulated storage container of large volumetric capacity having a working pressure not to exceed approximately 500 pounds per square inch absolute and adapted to be filled substantially to its volumetric capacity with liquid carbon dioxide at a subatmospheric temperature not to exceed 32 F., means for effecting refrigeration of the carbon dioxide while maintaining all of the same stored in said container by condensing vapors in the vapor space of said container at a rate which will prevent a rise in vapor pressure above the working pressure of the container, and means for conducting the liquid carbon dioxide at approximately its stored subatmospheric temperature to a point of use.

3. A iire extinguishing system comprising an insulated storage container adapted to be illled substantially to its volumetric capacity with liquid carbon dioxide at a subatmospheric temperature, mechanical means for effecting refrigeration of the carbon dioxide stored -n said container, while maintaining all of the same conned against loss, by reconverting to liquid the vapors i which are formed as a result of absorption of heat through the insulation of the container, and means for conducting the liquid carbon dioxide at substantially its stored subatmospheric temperature to a point of use.

4.' A re extinguishing system comprising an insulated storage container adapted to be filled substantially to its volumetric capacity with liquid carbon dioxide at a subatmospheric temperature not to exceed 32 mechanical means for eiiecting refrigeration of the carbon dioxide stored in said container, while maintaining all of the same confined against loss, by reconverting to liquid the vapors which are formed as a result of absorption of heat through the insulation of the container, and means for conducting the liquid carbon dioxide at its stored subatmospheric temperature to a point of use.

5. A re extinguishing system comprising an insulated storage container having a Working pressure substantially below the vaporI pressure of carbon dioxide at atmospheric temperature and adapted to be iilled substantially toits volumetric capacity with liquid carbon dioxide at a subatmospheric temperature, the corresponding vapor pressure of which will not exceed the working pressure oi the container, a mechanical refrigerating apparatus including an evaporator and means for conducting the liquid carbon dioxide at substantially its stored subatmospheric temperature to a point of discharge.

6. A re extinguishing system comprising a storage container including a vapor receiving dome and having a working pressure substantially below the vapor pressure of carbon dioxide at atmospheric temperature adapted to be illled substantially to its volumetric capacity with liquid carbon dioxide at a subatmospheric temperature, the corresponding vapor pressure oi which will not exceed the working pressure ot the container, insulating means for the entire container, a mechanical refrigerating apparatus including a cooling coil arranged in the vapor receiving dome of the container and operating to prevent a rise in vapor pressure above the working pressure of the container by condensing vapors coming in contact with said coil and returning the condensation by gravity directly to the liquid bath, and means for conducting the liquid carbon dioxide at a subatmospheric temperature to a point of discharge.

7. A re extinguishing system comprising an insulated storage container having a working pressure substantially below the vapor pressure of carbon dioxide at atmospheric temperature and adapted to be illled substantially to its volumetricy capacity with liquid carbon dioxide at a subatmospheric temperature, the corresponding vapor pressure of which will not exceed the working pressure of the container, a mechanical refrigerating apparatus including a cooling coil arranged in the vapor space of the insulated storage container to prevent a rise in vapor pressure above the working pressure of the container by condensing vapors coming in contact with said coil and returning the condensation by gravity directly to the liquid bath, a relief valve in communication with the vapor space of the container and set to bleed vapor from the container when the vapor pressure in the container rises above the pressure which corresponds with the temperature at which the refrigerating apparatus is intended to maintain the stored .carbon dioxide but before the vapor pressure reaches the working pressure of the container, and means for conducting the liquid carbon dioxide at substantially its stored subatmospheric temperature to a point of discharge.

8. A ilre extinguishing system comprising a storage container including a vapor receiving dome and having a working pressure substantially below the vapor pressure of carbon dioxide at atmospheric temperature adapted to be filled substantially to its volumetric capacity with liquid carbon dioxide at a subatmospheric temperature, the corresponding vapor pressure of which will not exceed the working pressure of the container, insulating means for the entire container, a mechanical refrigerating apparatus including a cooling coil arranged in the vapor receiving dome of the storage container to prevent a rise in vapor pressure above the working pressure of the container by densing vapors coming in contact with said coil and returning the condensation by gravity directly to the liquid bath in the container, a relief valve in communication with the vapor space of the container and set to bleed vapor from the container when the vapor pressure in the container rises above the pressure which corresponds with the temperature at which the refrigerating apparatus is intended to maintain the stored carbon dioxide but before the vapor pressure reaches the working pressure of the container, and means for conducting the liquid carbon dioxide at substantially its stored subatmospheric temperature to a point of discharge.

9. A iire extinguishing system comprising a storage container having a working pressure substantially below the vapor pressure of carbon dioxide at atmospheric temperature and adapted to be iilled substantially to its volumetric ca- 5 pacity with liquid carbon dioxide at a subatmospheric temperature, the corresponding vapor pressure of which will not exceed the working pressure of the container, a mechanical refrigerating ap- :Lparatus including an evaporator coil arranged in heat exchange relation with the vapor of the storage container to prevent a rise in vapor pressure above the working pressure of the container by condensing the vapors and returning the condensation to the liquid bath, andl means for conducting the liquid carbon dioxide at a subatmospheric temperature to a point of discharge. v

10. A fire extinguishing system comprising a i storage container including a vapor receiving space in communication with the container and zo having a working pressure substantially below the vapor pressure of carbon dioxide at atmospheric temperature adapted to be filled substantially to its volumetric capacity with liquid carbon dioxide at a subatmospheric temperature, the corresponding vapor pressure of which will not exceed the working pressure of the container, a mechanical rei'rigerating apparatus including a cooling coil arranged inthe said vapor receiving space of the container to prevent a rise in vapor pressure above the working pressure oi the container by condensing vapors coming in contact with said coil and returning the condensation by gravity directly to the liquid bath in the container, and means for conducting the liquid carbon dioxide at a subatmospheric temperature to a point of discharge.

11. A nre extinguishing system comprising an insulated storage container adapted to be fined substantially to its volumetric capacity with 4 liquid carbon dioxide at a subatmospheric temperature, a mechanical refrigerating apparatus including a cooling coil arranged in the vapor 4|- corresponds with the subatmospheric temperature otthechargedcarbondioxidebycondensing tiallyitntoredherictemperaturetoa pointotdischarge.

11AM systemen insulated storage container adapted to be lled substantially to its volumetric capacity with liquid carbon dioxide at a subatmospheric temperature not to exceed 32 F., said container including a dome arranged to receive vapor rising 5 c from the liquid bath in the container, a mechani- 4 contact with said coil and returning the condensation by gravity directly to the liquid bath in the container, and means for conducting the 15 liquid carbon dioxide at substantially its stored subatmospheric temperature to a point of discharge.

13. A nre extinguishing Asystem comprising an insulated storage container having a capacity of 20 several hundred pounds of liquid carbon dioxide and a working pressure substantially below the vapor pressure of carbon dioxide at atmospheric temperature and adapted to be lled substantially to its' volumetric capacity with liquid carbon 25 dioxide at a subatmospheric temperature, the corresponding vapor pressure oi which will not exceed the working pressure ot the container. a mechanical reirigerating apparatus including an evaporator coil located within the interior of the s0 storage container in heat exchange relation to the carbon dioxide stored therein and connected by piping to the remainder oi the apparatus which is located outside ot said container, a piping sysbon andavalve device ioreachbranch line operable toselectthepointorpointsoidischargeatter carbon dioxidehasbeentin-nedinto pipingsystembytheiirstmentionedvalve BICGIBTZ. 

